Multi-pass muffler

ABSTRACT

A muffler construction provides a flow path through a tubular shell which has four reversals in direction by means of a novel arrangement of tubular elements and only a single partition.

United States Patent Andres [4 1 Mar. 28, 1972 [54] MULTI-PASS MUFFLER 1,131,233 3/19l5 Gorosa ..l8l/53 2,038,309 4/1936 Oldberg..... [72] Invent Andres Jacksm 2,675,088 4/1954 McLeod [73] Assignee: Tenneco Inc., Racine, Wis. 3,361,227 1/1968 Kaari ..181/54 1 Fi1ed= July 24, FOREIGN PATENTS OR APPLICATIONS [211 P 58,124 593,282 10/1947 Great Britain ..181/53 521 U.S. Cl ..1s1 s3, 181/63 Primary Examiner-Robert 8. Ward. [51] Int. Cl .F0ln 1/08, F0111 7/18 Attorney-Harness, Di y & Pi rc [58] Field of Search ..18l/48, 53-55,

181/59, 63, 68-70 [57] ABSTRACT A muffler construction provides a flow path through a tubular [56] References Cned shell which has four reversals in direction by means of a novel UNITED STATES PATENTS arrangement of tubular elements and only a single partition. 3,485,319 12/1969 Balluff ..181/54 5 Claims, 2 Drawlng Flgures I; X r X LI Ef/ Q FL) iT/ u Ill T n u i jh PATENTEnmARzs m2 INVE TOR. 777 76 MULTl-PASS MUFFLER BRIEF SUMMARY OF THE INVENTION It is the purpose of this invention to provide a small cross section muffler with multi-directional gas flow by means of a simple arrangement of internal structural elements. The invention accomplishes this by means of a muffler shell having aligned inlet and outlet tubes which are longitudinally spaced from a central partition that is carried by an enlarged tubular element that overlaps both the inlet and outlet tubes.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross section through a muffler in accordance with this invention; and

FIG. 2 is a cross section along the line 2-2 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION The muffler 1 has a housing 3 which may be formed from circular tubing that is reduced in diameter at opposite ends to provide an inlet bushing 5 and an outlet bushing 7 which are concentric with the axis of the shell 3. An inlet tube 9 is supported in and spotwelded to the inlet bushing 5 and an outlet tube 11 is supported but slidable in the outlet bushing 7 to accommodate differential expansion. Overlapping the tubes 9 and 11 and covering the space between the inner ends of the tubes is a relatively large diameter intermediate tube 13 which is tangent to the tubes along the line 15 and spotwelded to them as indicated by the x markings at 17. The tube 13 is substantially larger in diameter than either of the tubes 9 and 11 and at its midpoint has a transverse baffle or partition 19 spotwelded in place. The partition 19 is preferably imperforate as illustrated.

The simple construction described provides a gas flow path that reverses direction four times as can be seen by reference to FIG. '1. The inlet gas entering the muffler through tube 9 is caused to reverse in direction by the partition 19 and flow toward the inlet end of the muffler through the interior of tube 13. At the open end of the tube 13 the gas again reverses direction and flows through the volume of the space 21 between the shell 3 and the tube 13. It passes along the length of the muffler until it reverses direction to enter the other end of the tube 13 and flow back toward partition 19 where it is reversed in direction so that it enters by outlet tube ll and flows out of the muffler through the bushing 7.

The tubes 9 and 11 are perforated, preferably in the form of patches of louvers 23 which are illustrated as located within the tubing 13. The tube 13 also is perforated preferably in the form of a patch of louvers 25. The louvers 23 and 25 in combination with the adjacent volumes provide high frequency sound roughness attenuation and permit some cross bleeding.

The various changes in direction of the gas and the several variations in the areas of the paths through which the gas flows abstract substantial sound energy so that the gas leaving the muffler is relatively quiet. Because of the small size of the unit and the nature of the sound attenuation in it, which is particularly effective in attenuating medium and high frequencies, the muffler of this invention has a special application on sports cars where some power sound of the lower frequencies is desired.

I claim:

1. A mufiler for attenuating sound in flowing gas comprising a housing having an inlet at one end and an outlet at the other end, an inlet tube in the housing connected to the inlet and an outlet tube in the housing connected to the outlet, the inner ends of said tubes being open and longitudinally spaced from each other, an intermediate tube in the housing telescoped over the inner ends of both the tubes and larger in cross sectional area than the tubes, said intermediate tube having open outer ends and containing a partition means located between and spaced from the inner ends of the inlet and outlet tubes and separating said tubes from each other, said inlet and outlet being coaxial surfaces and the outer ends of the inlet and outlet tubes bemg supported thereon, said intermediate tube being tangent to the inlet and outlet tubes and secured to them.

2. A muffler as set forth in claim 1 wherein the partition means comprises a transverse wall secured in position in the intermediate tube.

3. A muffler as set forth in claim 2 wherein said wall is imperforate.

4. A muffler as set forth in claim 1 wherein an overlapped portion of at least one of the tubes is perforated.

5. A muffler as set forth in claim 1 wherein the overlapping portions of the inlet and outlet and intermediate tubes are provided with louver patches. 

1. A muffler for attenuating sound in flowing gas comprising a housing having an inlet at one end and an outlet at the other end, an inlet tube in the housing connected to the inlet and an outlet tube in the housing connected to the outlet, the inner ends of said tubes being open and longitudinally spaced from each other, an intermediate tube in the housing telescoped over the inner ends of both the tubes and larger in cross sectional area than the tubes, said intermediate tube having open outer ends and containing a partition means located between and spaced from the inner ends of the inlet and outlet tubes and separating said tubes from each other, said inlet and outlet being coaxial surfaces and the outer ends of the inlet and outlet tubes being supported thereon, said intermediate tube being tangent to the inlet and outlet tubes and secured to them.
 2. A muffler as set forth in claim 1 wherein the partition means comprises a transverse wall secured in position in the intermediate tube.
 3. A muffler as set forth in claim 2 wherein said wall is imperforate.
 4. A muffler as set forth in claim 1 wherein an overlapped portion of at least one of the tubes is perforated.
 5. A muffler as set forth in claim 1 wherein the overlapping portions of the inlet and outlet and intermediate tubes are provided with louver patches. 